Biological fungicide Trianum-P now registered for pears

Pear losses halved by biofungicide

Good news for pear growers in the Netherlands and Belgium is that the biological fungicide – Trianum-P – has been registered in these two pear-growing countries and is ready for use against Brown spot. Bioprotection leader, Koppert, was given the official go-ahead by the authorities earlier this month. Many pear growers have incurred heavy losses to this harmful fungus in recent years.

The biofungicide, Trianum, which has been registered in the Netherlands and Belgium for several outdoor crops, has now obtained minor usage permission for pears; specifically to treat Brown spot. This label extension was acquired with the help of the NFO (Dutch Fruit Organization) and Fruit Consult (an independent advisory company). Swift action by the Dutch food and consumer safety authorities, NVWA and CTGB, has assured a smooth process.

Brown spot, Stemphylium versicarium, causes dark spots on fruits and leaves. Infection takes place throughout the season and often becomes eminent a few weeks before harvest. The affected pears are not marketable. Brown spot survives on dead organic matter on the ground in pear orchards during winter. In spring it starts to develop and creates spores. These spores are dispersed by wind and infect the crop. In 2022 several producers suffered losses of up to 60% of their harvest. Estimations show that 10% of orchards in the Netherlands and Belgium are affected by Stemphylium versicarium from time to time.

Successful trials in pears

Trials using Trianum-P have been conducted since 2015, but growers have had to wait for official registration of this product before being able to use it in pears: ‘Independent research trials in both the Netherlands and Belgium, have shown it to reduce fruit losses in pears of up to 50%,’ says Koppert Product Manager, Tim Bos.

Trianum-P is based on the Trichoderma harzianum T22-strain. Research in Italy – where Brown Spot is a big problem - and later in the Netherlands and Belgium by Fruit Consult and CAF (Central Fruit Growers Advisory Body) among others, has shown that Trianum-P can be a part of the solution to control Brown spot.

The Netherlands and Belgium both have a maritime climate that is ideally suited for the cultivation of pears. Producers have welcomed the registration of an effective biological solution. ‘We involved ten pear producers from various parts of the Netherlands and Belgium in our trials, and they were suitably impressed by the effect Trianum-P has as a preventive and sustainable solution,’ Bos shares.

How Trianum-P works

Trianum-P is sprayed full field on the ground - both on the grass lane as well as on the vegetation-free strip. The spores then germinate and start to grow, competing with the Brown spot (Stemphylium versicarium) fungus that is already present on the soil. The antagonistic characteristics of Trianum-P reduce the growth of the soil-borne Stemphylium, resulting in a lower number of infective ascospores, and hence less infection by Stemphylium.

‘Trianum is not a ‘silver bullet’, but definitively helps to control Brown spot and can be used within an integrated disease management scheme,’ Bos assures. ‘Our experience in Belgium last year has shown that it is important to take the moment of application into account. Trianum needs a soil temperature of at least 10 degrees Celsius and is best applied on moist soil. Furthermore, it should not be mixed directly with other fungicides when it is used in an integrated programme.’